189480

Appears in sequences

• Triangle read by rows: T(n,k) is the number of weakly connected acyclic digraphs on n labeled nodes with k arcs, k=0..n*(n-1).at n=31A350909
• Triangle read by rows: T(n, k) = [x^k] Sum_{j=0..n} FallingFactorial(n, j)*RisingFactorial(x, j).at n=24A391008